Rich Kozick
Spring, 1997

EE 329: Homework 4

Date Assigned: Friday, February 14, 1997
Date Due: Wednesday, February 19, 1997

  1. Please read Chapter 3 in the textbook. Also review other books and notes on discrete-time systems and Z transforms that you may have from previous courses.

  2. You are given two data files, sig1.dat and sig2.dat. These are both ASCII files, and they can be loaded into Matlab with the command

    load sig1.dat -ascii

    after which a variable named sig1 will be available. (The same can be done with sig2.dat.) Both files were recorded by sampling at a rate of 60 samples per second.

    Your job is to analyze each file separately, and decide which of the following statements are true for each file:

    You can assume that 40 Hz and 50 Hz are the only possible sinusoidal signals that can be present in the data. That is, no lower or higher frequencies are present. You should plot the time signals for each case. The spectrogram may be useful for one or both files.

    Is it possible to answer the question? Clearly explain your reasoning.

Thank you.